✨(backend) give an order to choices

We are going to need to compare choices to materialize the fact that
choices are ordered. For example an admin role is higer than an
editor role but lower than an owner role.

We will need this to compute the reach and role resulting from all
the document accesses (resp. link accesses) assigned on a document's
ancestors.

src/backend/core/api/serializers.py

@@ -12,7 +12,7 @@ from django.utils.translation import gettext_lazy as _
 import magic
 from rest_framework import exceptions, serializers
 
-from core import enums, models, utils
+from core import choices, enums, models, utils
 from core.services.ai_services import AI_ACTIONS
 from core.services.converter_services import (
     ConversionError,
@@ -97,7 +97,7 @@ class BaseAccessSerializer(serializers.ModelSerializer):
 
             if not self.Meta.model.objects.filter(  # pylint: disable=no-member
                 Q(user=user) | Q(team__in=user.teams),
-                role__in=models.PRIVILEGED_ROLES,
+                role__in=choices.PRIVILEGED_ROLES,
                 **{self.Meta.resource_field_name: resource_id},  # pylint: disable=no-member
             ).exists():
                 raise exceptions.PermissionDenied(